1. Field Of The Invention
The invention relates to instruments and more particularly to instruments attachable to conventional watthour meters for generating a pulsed signal having a predetermined relationship to the rate of electrical power usage.
2. Description Of The Prior Art
U.S. Pat. No. 4,063,661 discloses an electric load researchdevice. This patent also describes other prior art devices which require an interconnection between the watthour meter and the external terminal unit and further indicates that these devices are sometimes not adaptable to ringless meter sockets. The instrument which is the subject of this patent requires that the conventional watthour meter be replaced by a modified meter which includes a pulse generator. Additionally, the cabling extends through the meter cover.
U.S. Pat. No. 4,110,814 discloses a watthour meter for use with remote reading devices. The watthour meter enclosure includes an opening therein through which a cable extends for connecting the data sending unit to an external recording instrument.
U.S. Pat. No. 4,491,789 discloses another embodiment of an electrical meter for measuring various parameters related to electric energy consumption. Signals representative of the rate of electrical energy use are coupled as inputs to a time of day multi-function register. The multi-function register communicates by way of light radiation with an external programmer/reader unit.
U.S. Pat. No. 4,298,839 discloses an electrical watthour meter communicating with external devices through an interface using radiated light signals.
U.S. Pat. No. 4,121,147 illustrates an electrical watthour meter for indicating the demand or rate of power usage which is adapted to be mounted between a standard meter socket and a standard meter.
U.S. Pat. No. 3,783,343 further illustrates the art related to watthour meters and discloses apparatus for mounting a watthour meter such that the watthour meter is totally enclosed in a container to protect it from external damage or vandalism.
Electric watthour meters of the variable rate type are further illustrated in U.S. Pat. No. 4,082,999. This invention provides apparatus permitting a standard watthour meter to be controlled such that the rate reduction is automatically calculated by programming the meter.